The history of medical x-ray imaging originates approximately to the time of inventing x-radiation. For more advanced ways of imaging, e.g. the development of panoramic x-ray imaging in the dental field started for over a half century ago. The development of digital imaging especially in the 1990s brought digital x-ray imaging devices also to dental practices. The latest development step in the dental field has been the generalisation of the cone-beam computed tomography apparatus designed for three-dimensional imaging of skeletal structures of the cranial area. Concerning new possibilities offered by them, worth mentioning is e.g. applications related to implant attachment and other treatment planning.
Along with the development of cameras and information technology, such as that of computing power of computers, it has become possible to create virtual three-dimensional surface models of different surfaces. In the dental field, facial surface models can be utilised e.g. in connection with orthodontic treatment, as orthodontic treatment can also have an effect on facial shapes. Such surface models have sometimes been combined with information on surface texture, i.e. that of details of the surface/surface structure.
The prior art also includes techniques to create a virtual three-dimensional texture model without a separately created model of the three-dimensional shape of the surface.
Among others, the need for acquiring a separate device for a particular imaging purpose has been limiting utilisation of facial texture models in the dental field. Acquiring a separate device is not only a question of costs but also of space, as each device always requires a space to be installed and/or stored in and/or where it can be used. On the other hand, each separate imaging always takes a certain amount of time, too. Furthermore, as far as data processing is concerned, there are certain challenges in the arrangements in which creating the model requires combining image information acquired at different times, image information acquired by different imaging devices and/or image information acquired of an anatomy having been positioned in different ways for imaging.